A Consequence of Dispersity on the Self-Assembly of Amphiphilic Homopolymers Containing Main-Chain Azobenzene
A Consequence of Dispersity on the Self-Assembly of Amphiphilic Homopolymers Containing Main-Chain Azobenzene
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分散对含主链偶氮苯的两亲性均聚物自组装的影响
DOI：
10.1002/macp.202100202
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发表时间：
2021-09-15
影响因子：
2.5
通讯作者：
Zhu, Xiulin
中科院分区：
文献类型：
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作者：
Hu, An;Shi, Xianheng;Zhu, Xiulin
两亲性低聚物/聚合物的自组装是制备非球形聚合物纳米颗粒的一种通用且有前途的方法。具有分子限定结构的离散两亲性低聚物/聚合物是制造智能纳米颗粒和实现结构控制自组装的更深入理解的理想候选物。本文设计并合成了PAZO（n）TEG（2n）与疏水偶氮苯的离散和分散的两亲性均聚物，并将其作为主链与亲水性四甘醇单甲醚（TEG）单元相连接，以准确地研究分散性对其在溶液中自组装的影响。分散态PAZO（8）TEG（16）在DMF/水和THF/水溶液中形成二维层状结构，而分散态PAZO（8）TEG（16）则倾向于自组装成球形胶束。这种显著的差异是由于它们在装配内部结构之间的区别。此外，偶氮苯的光异构化引发离散的聚合物纳米粒子的解离/重新组装，但分散的对应物在紫外/维斯光照射下没有明显的变化。这项工作揭示了分散性对两亲性聚合物的自组装及其纳米材料的刺激响应特性的影响，这对于制造智能2D薄片的普遍适用性是理想的。
The self-assembly of amphiphilic oligomers/polymers is a versatile and promising approach for creating nonspherical polymeric nanoparticles. Discrete amphiphilic oligomers/polymers with molecularly defined structures are ideal candidates for fabricating smart nanoparticles and for achieving a deeper understanding of structure-controlled self-assembly. Herein, discrete and disperse amphiphilic homopolymers of PAZO(n)TEG(2n), with hydrophobic azobenzene are designed and synthesized as the main chains tethered with hydrophilic tetraethylene glycol monomethyl ether (TEG) units, to accurately investigate the impact of dispersity on their self-assembly in solution. The discrete-PAZO(8)TEG(16) in DMF/water and in THF/water results in the formation of 2D lamellae, while the dispersed counterpart prefers to self-assemble into spherical micelles. The significant difference is due to their distinction between interior structures of assembly. Furthermore, photoisomerization of azobenzene triggers dissociation/reassembly for discrete polymeric nanoparticles but no obvious change for the dispersed counterparts under irradiation with UV/vis light. This work reveals the influence of dispersity on the self-assembly of amphiphilic polymers and stimuli-responsive properties of their nanomaterials, which is desirable for universal applicability in fabricating smart 2D lamellas.